code: def test_layer_tracking(self):
      class NestedLayer(layers.Layer):
          def __init__(self, units):
              super().__init__()
              self.dense1 = layers.Dense(units)
              self.layer_dict = {
                  "dense2": layers.Dense(units),
              }
              self.layer_list = [layers.Dense(units)]
              self.units = units
  
          def build(self, input_shape):
              self.layer_list.append(layers.Dense(self.units))
  
          def call(self, x):
              x = self.dense1(x)
              x = self.layer_dict["dense2"](x)
              x = self.layer_list[0](x)
              x = self.layer_list[1](x)
              return x
  
      class DoubleNestedLayer(layers.Layer):
          def __init__(self, units):
              super().__init__()
              self.inner_layer = NestedLayer(units)
  
          def call(self, x):
              return self.inner_layer(x)
  
      layer = NestedLayer(3)
      layer.build((1, 3))
      self.assertLen(layer._layers, 4)
      layer(np.zeros((1, 3)))
      self.assertLen(layer.weights, 8)
  
      layer = DoubleNestedLayer(3)
      self.assertLen(layer._layers, 1)
      layer(np.zeros((1, 3)))
      self.assertLen(layer.inner_layer.weights, 8)
      self.assertLen(layer.weights, 8)
  
imports: import numpy
  import pytest
  from keras import backend
  from keras import layers
  from keras import metrics
  from keras import models
  from keras import ops
  from keras import testing
label_desc: Use image node_id 4 for calling the LayerTest obj's underlying member method code with example usage: obj.test_layer_tracking() and returns: x, self